2. The flu vaccine will definitely keep you from getting the flu.

False, sadly. There are many different flu viruses and the vaccine can’t protect people against all of them. Also, the vaccine may work less well in older people or those with depressed immune systems.

3. Being cold causes a cold.

This is probably mostly not true. Some researchers say being cold (as long as you don’t get hypothermia) can actually boost the immune system. But all the changes in temperature people experience in the winter (going from cold outdoors to heated houses, for instance) can clog up their noses, making them more likely to get colds. Also, one study showed that people forced to keep their bare feet in ice-cold water were more likely to get colds. They were also more likely to be mad at the study authors.

4. Feed a cold, starve a fever.

Yeah, not really. Nutrition scientist Denise Snyder says this adage “was always pretty much dismissed as folklore.” It’s possible that eating less when you have a fever could boost your immune response, but it’s not worth starving yourself. And while eating during a cold could keep your nutrient levels up, it’s not like you’ll really be able to avoid it, since colds last a while anyway. Snyder says people should focus less on food and more on what’s proven to make illness shorter, like rest and fluids.

5. Pregnant women shouldn’t get the flu shot.

Actually, pregnant women are especially prone to getting sick from the flu, because of immune system changes during pregnancy. And if a pregnant woman gets a flu shot, the vaccine will offer some protection to her newborn too. However, pregnant women shouldn’t get the flu vaccine in nasal spray form.

6. Healthy young people shouldn’t get the flu shot.

In the past when vaccine became scarce, flu shots have been restricted to at-risk groups like the elderly. But as long as there’s no vaccine shortage, anyone older than 6 months can benefit from a flu shot.

7. Vitamin C prevents colds.

Sorry, taking vitamin C regularly doesn’t make you less likely to get a cold — unless you’re a marathon runner, in which case it might have some effect. For normal people, taking the vitamin daily might make colds you do get slightly shorter.

8. Zinc cures colds.

According to the Mayo Clinic, most reliable research shows that zinc has no effect on colds. A study earlier this year found that zinc might make colds shorter, but the lead author still said there was “only a weak rationale for its use in adults.”